Hi.
In terms of size, the Asus-210 is a much smaller card, it is also much slower for games, uses very little electricity. (250w)
The GTX 950 is a medium size card, and is much more powerful, it needs a good system with a good power supply (450w), much better for games.
Both cards will fit inside the chassis listed (Iball-6363) (standard chassis)
The power supply that comes included with the Iball-6363 is very bad, I would suggest a new PSU.